Separating solids from liquids



Jan. 5 192s. 1,568,249

0 SODERLUND ETAL.

SEPARATING somns FROM LIQUIDS Filed August 30. 1923 4 Sheets-Sheet 1 1%. fasira r8 Jan. 5 1926. 1,568,249

0. SODERLUND ET AL SEPARATING SOLIDS FROMf'LIQUIDS Filed August 30 1 1923 4 Sheets-Sheet :5

five/ 77 076 N 7652 7540 T Bo Ber 15 M Jan. 5, 1926. 1,568,249

0. SOD E RLUND ET AL SEPARATING SOLIDS FROM LIQUIDS Filed August 30, 1923 4 Sheets-Sheet 4 Patented Jan. 5, 1926.

UNITED 'iSTATEFS .iea'reu'r o-FFicE.

OLOF soDERLUND, mEoFnoN BQBERG, AND -NILs \TE'STRUP, OF LONDON, ENGLAND,

ASSIGNORS T0 TECHNO-CHEMICALLABORATORIES, LIMITED, or LONDON, ENG- LAND.

snmmrrme' somns FROM mieor'ns.

"Application flledlugust 30, 1923. Serial -No. 660,234.

T 0 cl! c/zom-z't may concern:

Be it known that we, OLOF sfiDERLU'ND and li-iomioN Bonnno, b0thsub ects0f the King of Sweden, and both residing at Fairlawn,

for example, in peat,'lignite, vegetable matter such "as seeds and many other materials from which it is frequently desired to separate or expel some of the liquid content for the-purpose of bringing the material to a dry or-drier stateor separating liquid which -isto serve some useful purpose.

The-entry orbite of a pair of rolls coactingtogether to effecta squeezing operation for-separatin liquid as above is of a configurationgenerallyresembling a-wedge with inwardly curved or hollowed'sides instead of plain taperingones. The-angle between the sides'will, therefore, vary from a maximum at the large end to a minimum or zero at the'apex or locality of maximum pressure where the rolls most closely approach one another.

Depending upon the nature of the mate rial being pressedthere will be some limiting angle and/or distance between the pressing surfa'ces beyond which theforcesftending to drive the material out of the bite will overcome those tending to draw it in, but thc'grcater 'the distance of this 'region from the locality ofma'ximum' pressure on the ma terial the greater will be the output from the machine for several reasons.

The object of the present-invention is to provide improved methods of and/ or apparatus for reducing or separating by asqueezing action the liquid content of materials.

The invention consists in a method of and/or apparatus 'for obtaining increased output from appliances of the-type indi- (rated, according to which carrying or feed ing memlierss rch as endless bands are arranged to'travel through the biteof the rolls with the material undergoing treatment.

The invention further consists in a method "and/or "apparatus a's'indicated, in which a localized'stream or'trail of matter is applied, preferably inthe centre, to the moviing surface or surfaces and by a rolling or like pressure is "spread'thereon to a thinner :and broader-strip of'drier consistency from which the -separated liquid or wetter portion "is expelled-more or'less transversely in more "than one direction.

The invention further consists in a methodas indicated according to which heat treatment or further drying or reduction of the liquid content of the thin strip is effected 'lry'supplyiug heat to the surface or material thereon.

The invention further consists in amethod and/orapparatus as-indicated, in which the material is pressed between two surfaces \vhichmurve in the-same direction as'when the external surface of a cylinder coacts with the internal-surface of a hollow cylinder or encircling" member.

The invention also consists in improve- "mentsin -or relating to the reduction or separation of'the liquid content of moist or liquid-bearing materials ashereinafter described.

Referring now to the accompanying draw- Figures 1, 2, 3 and 4 are diagrams shownrg the'difi'ere'nce 1n the entry or bite of various 'rollers and otherpressing and carrying surfaces;

Figure 5 is a perspective view of amultibandpre' ss looking at the entry or feeding side;

Figure 6 is a similar View, but looking from the other side Figure 7 1s adiagrammatio plan show- -ing the entry or bite of a pair of vertical rolls;

I 1gu're8 as a fragmentary vertical section sh'owing'an embodiment for'feeding rolls of the foregoing type and it will be seen that the more or less wedge-shaped configuration of the space a where the material will enter between the rollers when rotating in the direction shown by the arrows is wide in proportion to its length and that the transverse dimensions or the distances between the periphery of the rollers decrease in such a manner that the red ction is very rapid and the inclination of the two surfaces to one another is cons'derable at the commencement and more gradual as the point of contact or maximum grip is reached. For this reason the material can only be properly gripped between the two sin-fares when it is very close to the point of maximum pressure and the amount of material carried through will, therefore, be small because if the space is tilled beyond a certain distance a very great proportion will be forced back owing to the outward resultant of the pressure on the material being greater than the frictional resistance to its movement along the press ing surfaces.

l ignre 2 shows the contact between a pair of rolls of very much greater diameter and here it will be noted that the transverse dimensions are much smaller in proportion to the length and that the variation in the transverse dimensions is of a much more uniform nature, while the inclination of the two surfaces to one another is much less. The material in the space a will, therefore, be gripped at a much greater distance from the region oi maximum pressure and a larger proportion will be carried through the grip. however, the size of a press hari rolls of these proportions would be. very great practical considerations would pr t such an arrangement being adopted with any degree of commercial success.

igure 3 shows an arrangement which in accordance with the invention provides for a greatly increased output by the arrangement of a carrying or feeding member in the shape of an endless band 3 which travels through the bite of the rolls with the matcrial undergoing treatment.

The rolls are of similar size to those shown in Figure 1 and the band 3, of which a short portion only is shown, may encircle one or other of the rolls 1, 2 and the pressure exerted upon it at the locality of maximum pressure is suliicient to ensure that it is driven at the same surface velocity as the rolls, so that it will provide upon each side of it an additional surface in contact with the material which is being fed in and capable of exerting a frictional grip thereon.

in addition the intern'iediate band, by halving the wedge-shaped cavity or bite, reduces both the angles which the contacts faces make with one another and also between the surfaces so that the 2 with the additioinrl hand the material may be fed to the bite at a consid rably greater distance from the locality of maximum pressure without a large proportion being rejected in the manner already indicated. This again gives a mucn greater length of travelling surface in contact with the ma terial and consequently a longer pressing time in addition to a greater frictional p on the material, so that under such circumstances the travelling surfaces may be run at a considerably higher speed. All of the above conditions result in a very greatly increased output from a machine which will be substantially the same as in the ease of Figure 1 with only the addition of the travelling hand between the rollers.

Figure l shows a pair of r lls of the same diameter as the rolls in Figure 1 but in this case three separate endless hands are arranged round each of the rolls, so that six bands pass together through the entry or bite. In this arrangement it is possible to provide seven separate entries of gradua ly decreasing transverse dimensions, each cavity resembling very closely a uniformly tapering wedge which may be slightly bent to a curvature in one direction or the other so that a very large amount of material may be gripped between the moving surfaces and all of it be drawn through the reg on of maximum pressure and thus subjected to the ne: essary squeezing action.

s an oxamyde of the improvement which may lre obtained by the use of gradually and :-:nhstantially uniformly tapering entry cavities and reduced distances and angles between the surface it has been found that with two drums having each a diameter of an inches there was obtained, when squeeging raw peat, an output in the ncighhou hood of 5 kg. of solids per hour per lineal metro surface, whereas when a ring with a diameter of 21": inches was put round one of these drums and raw peat was squeezed on one side of the ring only with the same pressure between the outer surface of the inner drum and the inner surface of the ring a much larger output, say in the neighborhood of some four times the amount of solids per hour per lineal metre surface, was obtained.

Two rolls in accordance with Figures 3 and i and provided with any suitable number of encircling bands may be arranged with the axes vertical, horizontal or in any other suitable direction parallel to one another, the rolls being mounted in a suitable frame with the distance apart adjustable so that room for the thickness of two or any greater number of rings or hands and the material carried thereby left between them. In this way it is possible to obtain in a single apparatus and by the addition only of the extra hands a squeezing capacity having entry cavities or bites of a far more ill) satisfactory configiwation and eapa-ble'of'an hrising upper-and lower horizontal inen'ibers (LIV and vertical connecting nieinbers cl d The roller b'issurmunded by twoflexible endless bands e, 0" and tl1eroll bis sur rounded by-'two-similar bands 6% 6 said fhands being suitably positioned hy guide rollers 'f and any othersupporting mea-ns (not shown in the drawing).

The foul-bands e, e, 6 e passtogether through the biteof the rolls .and upon the entry side there-is fitted a feedbox g to which material such as pulped' peat or other matter which-isto be,freed of part of its liquid content is delivered from a'feed'hop- I per g which maybe providedwith a taper feed worm or screw operating in a gradually tapering extended portion 9 The feed \box 9 coninuinicates with .the entry space formed between upper and lower cover plates g and {I -and a series of vertical positioning bar-s g extending from the upper to :the lower plate around the outer edge thereoi The upper plate is'perforated with a more or less sector-shapediaperture through which the peat passes from the feed box into the entry spaces z between the bands. The lower plate 9 covers the whole of the bottoms otthe entry spacesoand both plates overlap the edges of the two rolls. as shown by dotted linesat g in Figure 7. andyteu minate shortly before reaching the region of maximum pressnre as shown'at M. in order to provide spaces "for the extruded wetter or more liquid constituentsro't \the n'mttcr being: pressed. il hepositioning bars also constitute supports for scrapers 72, carried upon the outer sides thereo'taud adapted to coact with the surface of the rolls and both sides ofthe bands. The scrapers ren'iove the drier constituents 0t the matter from thebandsand rolls on to a chute h. from which it may hecarried tosany desirer .iloca-lity.

In some instances the material to be pressed passes into the bite as'ancontinuous layer extending the full width ofthe press ingz SNlTtN'QS of the handsand.l'(illers, l' iit in most instanves it ispreierableto :pmiiide surfaces upon each side of 1 gear pillar studs (-assshown at 2', Figures 7 and 8) which extendsacros each otthe teed cempartments from the upper tosthe lower cover plates and just beyond the inner edge or "the tecdapcrture inthe upper plate. pillar studs 1 are PI'OVIClOd with central slots or apertures i (Figure-8) which loca izethe "Feed to a restricted stri p occupying theicen- .tral portion of the pressing surfaces 01": a

a spaceon the the feed over which the n'ia-terialsn'zay rhesqueeZed-Y in a transverse direction, while themore liquid constituents are passing therefrom to be 1 extruded at'the edges ofthe surfaces.

In the embodiment otthe invention iillusband or roller and providing tratedby way of example in Figures and 8 5 power issupplicd to a pulley upon a horizontal shaft 7" communicating by bevel 5, 7 with, a verticalshatty icarru' -1l1 P;1z1t"1tS lowercnda pinion gearingwith toothed-wheel j on the spindle of one of "the rolls end gearing with another similar toothed wheel vj on ,thespindlewof theother usoll.

'lVipers -70, l1 and other suitable icon- "tzri'vances blowing; 'or suction ClGVlG/(BSQOJF the like may he provided forremoving(there);-

traded more liquid constituents -:-from the the bands and zrollers .and conducts portion of thematter treated --.hy means of suitable conduits (not showninthe drawing) to a tankiorotherlocation from which itinay'bedisposed of as-desired.

1? ignites 9 and lOshow in a more-or less dian anunatic manner another embodiment of :thcwinrentioin in which each of the rolls 1), Z/issurrounded by ten-travelling bands. thevban-dsbeing;supportedand positionec by til edge ru-nners Zqaudguide rollersf andspro uidetl :with-scrapers 72 for the dried material.

The rolls Zn W are. 1 till arr d with their axes vertical-and rotated on v -pindles carried in hearings071.1117? supported in a isuitahlegirder flfiill'llll and provided with 'hyd aulic cylinders nlor applying:the-desired pressure overzthe contact ai 'ea-sw'rt' the pressingsurfaces. The feeding .aud driving arrangements in this embodiment-are upon similar lines to those already described in connection with the embodiment shown in Figures 5 to 8.

The feeding-(rt .HIHH'QIIOH lo the pressing surfaces will be determined to soine extent centre of ,each rin Such .-,an arrangement,

may also be adopted, it desired, in the case of rigid bands or rings used in connection with such rolls.

For feeding a localized stream of matter tubular members may be inserted in each division of the bite slightly in front of the region at which the material will be satisactorily carried by the pressing surfaces and the tubular member may have a rightangled spout pointing into the bite, preferably in the centre of the width of the pressing surfaces, the spout being carried into the bite until substantially in contact with the pressing surface upon each side.

The n'iatter will be extruded from the spout by pressure in the tubular member and will issue as a cylinder or jet of the material to be pressed which almost immediately after issuing from the end of the spout will contact upon each side with the pressing surface and be carried and spread thereby into a broad strip of material from which the more liquid constituents are or:- truded upon each side. if desired, a bracket may project a small distance beyond the end of the spout in order to guide the jet of material until it is caught and supported by the pressingsurfaces.

Presses in accordance with this invention may be worked at any desired temperature and means for heati the interior of rolls or rigid and hollow bands may be provided. The heating employed may be of any desired nature, such as hot gases, live steam or recompressed vapour generated from previously treated matter, the thin and uniform films of matter produced by apparatus in accordance with the invention being particularly applicable to further drying by means of the small temperature differences which may be economically obtained when utilizing recompressed vapours.

The speeds of the moving pressing surfaces and the pressure exerted between them will be graduated in accordance with the material to be treated and the complete treatment of any particular type of matter may be split up into two or more stages in which the speeds and pressures are adapted to the condition of the material in its varying states.

In many instances, where matter of large liquid content is under consideration, the presses may be used in combination with draining, settling or filtering devices by means of which a portion of the liquid con stituent-s may be separated from the matter which may then be more easily treated in presses in accordance with this invention.

In presses provide-d with rings and bands these may in some instances be formed of different materials which cooperate together to give a better result for certain purposes as, for example, plain steel bands may be employed where heavy pressure is necessary or steel bands alternating with softer ma terial as, for example, rubber or the like, or two coacting soft bands may be employed for matter which could be satisfactorily treated by means of lighter pressures.

Presses in accordance with this invention may be employed for obtaining oils, fats and the like from suitable sources, such as seeds, beans, nuts and other organic products and in such cases provision for heating the rolls and/or bands is preferably provided for ob taining the best results. 7

hen treating matter from which a considerable amount of liquid is to be eliminated it is possible in accordance with this invention to so far reduce the liquid content that the matter may be conveniently broken up to an extent which enables it to be carried in a heated gaseous medium and drying of the solid constituents of the matter may, thererefore, be completed in the waste flue gases of boilers which may supply power for the presses or any hot gaseous medium obtained from other sources.

Where so desired the whole of the pressing apparatus may be surrounded by a casing: and heat may be introduced and any required temperature maintained therein, either in the atmosphere of the casing or hf g1 condensing steam in the interior of the two drums or in any other suitable man- By operating as hereinbefore described it is possible to obtain a very large output from apparatus of comparatively moderate dimensions and as only the two rolls require to be mounted in adjustable bearings and provided with devices for exerting the necessary pressure the apparatus will be of very much lower cost in relation to the amount of product obtained. Further, as the operative portions of the apparatus are all collected within a small area the amountof labour and supervision for operating such apparatus is very greatly reduced and at the same time the effect obtained is in every way equivalent to what could be otherwise obtained only by the use of press ing rolls of such large diameters that it would not be possible to employ them in practice.

Apparatus in accordance with the invention may be employed either for the collection of the drier or wetter constituents of the matter or for both purposes simultaneously and such presses are particularly suitable for separating out liquids from materials such as peat, moss litter, lignite, sewage, spent hops, brewers grain. oil seeds, vegetable extracts, sugar cane, beet chips, wood pulp, sawdust and, generally, all materials which can be filtered or from which moisture can be squeezed or extruded.

It is to be uneerstood that the apparatus hereinbefore described. is given by way of example only and that modifications and additions may be introduced Without in any way departing from the spirit of this invention.

Claims:

1. Apparatus for ren'ioving liquid from material containing it comprising in combination pressing rolls with their axes substantially parallel with one another and their circumferential surfaces closely adja cent, not less than one endless flexible band passing between said surfaces to divide into substantially equal compartments the more or less wedge-shaped cavity preceding the bite of the rolls, means for feeding to each compartment the material to be treated and means pressing the axes of said rolls towards one another.

2. Apparatus for removing liquid from material containing it, com rising in combination pressing rolls with their axes substantially parallel with one another and their circumferential surfaces closely adjacent, endless flexible bands surrounding said rolls and passing between said surfaces to divide into substantially equal compartments the more or less wedge-shaped cavity preceding the bite of the rolls, means for feeding to substantially the centre of the width of the bands in each compartment the material to be treated and means pressing the axes of said rolls towards one another.

3. Apparatus for removing liquid from material containing it comprising in combination pressing rolls with their axes sub stantially parallel with one another and their circumferential surfaces closely adjacent, not less than one endless flexible band passing between said surfaces to divide into substantially equal compartments the more or less wed e-shaped cavity preceding the bite of the rolls, means for feeding to each compartment the material to be treated, means pressing the axes of said rolls towards one another, and means for applying heat to the pressed material.

at. Apparatus for removing liquid from material containing it comprising in combination pressing rolls with their axes substantially parallel with one another and their circumferential surfaces closely adjacent, not less than one endless flexible band passing between said surfaces to divide into substantially equal compartments the more or less wedge-shaped cavity preceding the bite of the rolls, means for feeding to each con'qaartn'ient the material to be treated, means pressing the axes of said rolls towards one another, means for removing the pressed material from the surfaces to which it adheres and means for delivering the said material into a moving current of hot gaseous medium.

In testimony whereof we have signed our names to this specification.

OLOF soDEnLUNn. 'rnonnou BOBERG. NILS TESTRUP. 

